Why your pool is losing water — and what to do about it
Have you noticed that your pool level drops regularly? Before worrying about a leak, bear in mind that every pool loses water every day. It is an unavoidable phenomenon with several well-known causes.
Normal causes of water loss in a pool
Evaporation
This is the main cause. It depends on many factors: heat, sunshine, air humidity and wind speed. Evaporation is proportional to the exposed water surface — so a large pool loses more water in volume than a small one, even though the level drops by the same amount in both. In midsummer, a pool can lose up to 3% of its volume per day.
Splashing
A busy pool — especially one used by children or teenagers — loses significantly more water than one used by a retired couple. Games, jumping and diving all throw water out of the pool.
The liner
A liner membrane is not 100% watertight. A small daily loss is perfectly normal and does not necessarily mean there is a leak.
Filter cleaning (backwash)
Backwashing a sand filter uses between 200 and 500 litres of water each time. This loss is unavoidable and necessary.
The hydraulic system
Unlike the causes above, a leak in the hydraulic circuit (pipes, pump, skimmer) is not normal. If your losses seem unusually high, do the bucket test to tell evaporation from a leak.
→ Read our guide: Pool leak — how to carry out a simple diagnosis in 24 hours
How can I tell if my pool is losing too much water?
The general rule: a loss of 2 to 3 cm per week in summer is normal. Beyond that, suspect a leak. The bucket test is a simple, reliable way to check in 24 hours.
Protect your equipment this season
NivOmatic keeps your pool level constant 24/7, with no electricity and no supervision. Installed in 2 minutes. Made in France — €129.
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The solution: stop compensating for these losses by hand
These water losses are unavoidable. What is far less so is having to make up for them by hand. Checking the level, topping up regularly, the risk of forgetting and of the pump burning out while you are on holiday… it is wasted time and needless stress.
NivOmatic automatically compensates for all these losses — evaporation, splashing, liner — by keeping your pool level constant 24/7, with no electricity and no action on your part.
Installed in 2 minutes
Compatible with all pools
Made in France for over 15 years
2-year warranty
→ Not sure which model to choose? Read our selection guide
Frequently asked questions
My pool loses 2 cm a day — is that normal?
In midsummer during a heatwave, yes. Outside those conditions it is borderline — do the bucket test to check.
How can I avoid losing too much water while on holiday?
Install an automatic level regulator before you leave. NivOmatic keeps the level constant throughout your absence, without any intervention.
Can the liner be responsible for a large leak?
Yes, if the liner is punctured or split. In that case the loss is well over 3 cm per week — the bucket test will confirm it.
